Elastomeric compositions

ABSTRACT

The present invention includes compositions suitable for tire treads or sidewalls and other articles where abrasion resistance and flexibility are desirable. The invention includes a tire tread or sidewall made by combining a filler; a sulfur cure system; optionally at least one secondary rubber; and at least one halogenated terpolymer of C 4  to C 8  isoolefin derived units, C 4  to C 14  multiolefin derived units, and p-alkylstyrene derived units. Examples of suitable fillers include carbon black, silica, and combinations thereof. The present invention also includes a method of producing an elastomeric terpolymer composition comprising combining in a diluent C 4  to C 8  isoolefin monomers, C 4  to C 14  multiolefin monomers, and p-alkylstyrene monomers in the presence of a Lewis acid and at least one initiator to produce the terpolymer. Examples of suitable initiators include cumyl compounds and or halogenated organic compounds, especially secondary or tertiary halogenated compounds such as, for example, t-butylchloride, 2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy 2-phenyl propane (cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethyl ether)); the cumyl halides, particularly the chlorides, such as, for example 2-chloro-2-phenylpropane, cumyl chloride (1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene (di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene (tri(cumylchloride)); the aliphatic halides, particularly the chlorides, such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl), and 2-bromo-2,4,4-trimethylpentane (TMPBr).

FIELD OF INVENTION

[0001] The present invention relates to compositions ofisobutylene-based terpolymers. More particularly, the invention relatesto terpolymer compositions, wherein the terpolymer includes isoolefinderived units, styrenic derived units, and multiolefin derived units,the compositions being useful in tires, particularly in tire treads andtire sidewalls.

BACKGROUND OF THE INVENTION

[0002] Isobutylene-based terpolymers including isoolefin, styrenic, andmultiolefin derived units have been disclosed in U.S. Pat. No.3,948,868, U.S. Pat. No. 4,779,657; and WO 01/21672. To be useful in,for example, a tire tread or tire sidewall as part of a multi-componentautomobile tire, the terpolymer must desirably be both sulfur curable,and compatible with other rubbers such as natural rubber andpolybutadiene. Further, in order to serve as a tire tread, theterpolymer compositions must possess abrasion resistance as well astraction. These properties are often difficult to achieve together, asimproving one can often diminish the other.

[0003] Improving the traction properties of tire treads withoutsacrificing tread wear is thus highly desirable. Use ofisobutylene-based elastomers in blends with hydrocarbon diene-elastomersoften serves to increase tangent delta values at temperatures at orbelow about 0° C. (predicting potential improvements in tire wet andwinter traction). However, lab abrasion resistance is often decreased,predicting poorer tread wear. Use of isobutylene-co-p-methylstyrenecopolymers increases the compatibility of isobutylene-based elastomerswith hydrocarbon elastomers. Yet, co-vulcanization is still not achievedto a sufficiently high degree and lab abrasion resistance is still notat levels of NR, SBR and the like. Thus compound abrasion resistancestill needs to be further increased for isobutylene-based elastomerblends, while maintaining the potential traction benefits of thepolymer.

[0004] It is unexpected that the incorporation of a multiolefin derivedunit in a isobutylene/p-methylstyrene backbone would contribute to bothimproved traction and abrasion properties in elastomer compositions.Yet, the inventors here demonstrate, among other things, the practicaluse of certain isoolefinic terpolymers that incorporate multiolefins.More particularly, it has been discovered that these terpolymers areuseful in blends with natural rubber and the like due to improvedtraction and abrasion performance, thus making these compositions usefulin tire treads and sidewalls.

[0005] Other background references include U.S. Pat. Nos. 3,560,458 and5,556,907 and EP 1 215 241 A.

SUMMARY OF THE INVENTION

[0006] The present invention includes compositions suitable for tiretreads and other articles where abrasion resistance, traction andflexibility are desirable. The invention includes a tire tread made froma composition of at least one (i.e., one or more) filler; a sulfur curesystem; and optionally at least one secondary rubber; and at least onehalogenated terpolymer of C₄ to C₈ isoolefin derived units, C₄ to C₁₄multiolefin derived units, and p-alkylstyrene derived units. In oneembodiment, the terpolymer is halogenated. Examples of suitable fillersinclude carbon black, silica, and combinations thereof.

[0007] The present invention also includes a method of producing anelastomeric terpolymer composition comprising combining in a diluent,having a dielectric constant of at least 6 in one embodiment, and atleast 9 in another embodiment; C₄ to C₈ isoolefin monomers, C₄ to C₁₄multiolefin monomers, and p-alkylstyrene monomers in the presence of aLewis acid and at least one initiator to produce the terpolymer.Examples of suitable initiators include t-butylchloride,2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy-2-phenyl propane(cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethylether)); the cumyl halides, particularly the chlorides, such as, forexample 2-chloro-2-phenylpropane, cumyl chloride(1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene(di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene(tri(cumylchloride)); the aliphatic halides, particularly the chlorides,such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl),2-bromo-2,4,4-trimethylpentane (TMPBr), and2,6-dichloro-2,4,4,6-tetramethylheptane; cumyl and aliphatic hydroxylssuch as 1,4-di((2-hydroxyl-2-propyl)-benzene),2,6-dihydroxyl-2,4,4,6-tetramethyl-heptane, 1-chloroadamantane and1-chlorobornane, 5-tert-butyl-1,3-di(1-chloro-1-methyl ethyl) benzeneand similar compounds or mixtures of such compounds as listed above.

BRIEF DESCRIPTION OF DRAWING

[0008]FIG. 1 is a plot of tangent delta (G″/G′) values as a function oftemperature for example 10 (BrIBMS), 12 (BrIBIMS), 14 (SBB) and 16(SBR), all including in the composition carbon black, NR and BR.

DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention includes a method of makingisobutylene-based terpolymers including isobutylene derived units,styrenic derived units, and multiolefin derived units, and compositionsof these terpolymers and halogenated terpolymers. The terpolymers of thepresent invention can be made via carbocationic polymerization processesusing a mixture of at least the monomers, a Lewis acid catalyst, aninitiator, and a diluent. The polymerization is typically carried outeither in slurry or in solution. The copolymerization reactor ismaintained substantially free of impurities which can complex with thecatalyst, the initiator, or the monomers. Anhydrous conditions arepreferred and reactive impurities, such as components containing activehydrogen atoms (water, alcohol and the like) are desirably removed fromboth the monomer and diluents by techniques well-known in the art.

[0010] As used herein, the term “catalyst system” refers to and includesany Lewis Acid or other metal complex used to activate thepolymerization of olefinic monomers, as well as the initiator describedbelow, and other minor catalyst components described herein.

[0011] As used herein, the term “polymerization system” includes atleast the catalyst system, diluent, the monomers and reacted monomers(polymer) within the butyl-type reactor. A “butyl-type” reactor refersto any suitable reactor such as a small, laboratory scale, batch reactoror a large plant scale reactor. One embodiment of such a reactor is acontinuous flow stirred tank reactor (“CFSTR”) is found in U.S. Pat. No.5,417,930. In these reactors, slurry (reacted monomers) is circulatedthrough tubes of a heat exchanger by a pump, while boiling ethylene onthe shell side provides cooling, the slurry temperature being determinedby the boiling ethylene temperature, the required heat flux and theoverall resistance to heat transfer.

[0012] As used herein, the term “diluent” means one or a mixture of twoor more substances that are liquid or gas at room temperature andatmospheric pressure that can act as a reaction medium forpolymerization reactions.

[0013] As used herein, the term “slurry” refers to reacted monomers thathave polymerized to a stage that they have precipitated from thediluent. The slurry “concentration” is the weight percent of thesereacted monomers—the weight percent of the reacted monomers by totalweight of the slurry, diluent, unreacted monomers, and catalyst system.

[0014] The term “elastomer” may be used interchangeably with the terms“rubber”, as used herein, and is consistent with the definition in ASTM1566.

[0015] As used herein, the new numbering scheme for the Periodic TableGroups are used as in HAWLEY'S CONDENSED CHEMICAL DICTIONARY 852 (13thed. 1997).

[0016] As described herein, polymers and copolymers of monomers arereferred to as polymers or copolymers including or comprising thecorresponding monomer “derived units”. Thus, for example, a copolymerformed by the polymerization of isoprene and isobutylene monomers may bereferred to as a copolymer of isoprene derived units and isobutylenederived units.

[0017] As used herein the term “butyl rubber” is defined to mean apolymer predominately comprised of repeat units derived from isoolefinssuch as isobutylene but including repeat units derived from amultiolefin such as isoprene; and the term “terpolymer” is used todescribe a polymer including isoolefin derived units, multiolefinderived units, and styrenic derived units.

[0018] As used herein, the term “styrenic” refers to any styrene orsubstituted styrene monomer unit. By substituted, it is meantsubstitution by at least one substituent selected from, for example,halogen (chlorine, bromine, fluorine, or iodine), amino, nitro, sulfoxy(sulfonate or alkyl sulfonate), thiol, alkylthiol, and hydroxy; alkyl,straight or branched chain having 1 to 20 carbon atoms; alkoxy, straightor branched chain alkoxy having 1 to 20 carbon atoms, and includes, forexample, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy,secondary butoxy, tertiary butoxy, pentyloxy, isopentyloxy, hexyloxy,heptryloxy, octyloxy, nonyloxy, and decyloxy; haloalkyl, which meansstraight or branched chain alkyl having 1 to 20 carbon atoms which issubstituted by at least one halogen, and includes, for example,chloromethyl, bromomethyl, fluoromethyl, iodomethyl, 2-chloroethyl,2-bromoethyl, 2-fluoroethyl, 3-chloropropyl, 3-bromopropyl,3-fluoropropyl, 4-chlorobutyl, 4-fluorobutyl, dichloromethyl,dibromomethyl, difluoromethyl, diiodomethyl, 2,2-dichloroethyl,2,2-dibromomethyl, 2,2-difluoroethyl, 3,3-dichloropropyl,3,3-difluoropropyl, 4,4-dichlorobutyl, 4,4-difluorobutyl,trichloromethyl, 4,4-difluorobutyl, trichloromethyl, trifluoromethyl,2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl, 1,1,2,2-tetrafluoroethyl,and 2,2,3,3-tetrafluoropropyl.

[0019] As used herein, the term “substituted aryl” means phenyl,naphthyl and other aromatic groups, substituted by at least onesubstituent selected from, for example, halogen (chlorine, bromine,fluorine, or iodine), amino, nitro, sulfoxy (sulfonate or alkylsulfonate), thiol, alkylthiol, and hydroxy; alkyl, straight or branchedchain having 1 to 20 carbon atoms; alkoxy, straight or branched chainalkoxy having 1 to 20 carbon atoms, and includes, for example, methoxy,ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, secondary butoxy,tertiary butoxy, pentyloxy, isopentyloxy, hexyloxy, heptryloxy,octyloxy, nonyloxy, and decyloxy; haloalkyl, which means straight orbranched chain alkyl having 1 to 20 carbon atoms which is substituted byat least one halogen, and includes, for example, chloromethyl,bromomethyl, fluoromethyl, iodomethyl, 2-chloroethyl, 2-bromoethyl,2-fluoroethyl, 3-chloropropyl, 3-bromopropyl, 3-fluoropropyl,4-chlorobutyl, 4-fluorobutyl, dichloromethyl, dibromomethyl,difluoromethyl, diiodomethyl, 2,2-dichloroethyl, 2,2-dibromomethyl,2,2-difluoroethyl, 3,3-dichloropropyl, 3,3-difluoropropyl,4,4-dichlorobutyl, 4,4-difluorobutyl, trichloromethyl,4,4-difluorobutyl, trichloromethyl, trifluoromethyl,2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl, 1,1,2,2-tetrafluoroethyl,and 2,2,3,3-tetrafluoropropyl. An “aryl” group is any aromatic ringstructure such as a phenyl or naphthyl group.

[0020] Butyl-type rubber is an isobutylene-based polymer produced by thepolymerization reaction between isoolefin and a conjugated diene—ormultiolefinic—comonomers, thus containing isoolefin-derived units andmultiolefin-derived units. The terpolymers of the present invention areprepared in a manner similar to that for traditional butyl rubbersexcept that an additional comonomer (e.g., a styrenic monomer) is alsoincorporated into the polymer chains. The olefin polymerization feedsemployed in connection with the catalyst and initiator system (describedin more detail below) are those olefinic compounds, the polymerizationof which are known to be cationically initiated. Preferably, the olefinpolymerization feeds employed in the present invention are thoseolefinic compounds conventionally used in the preparation of butyl-typerubber polymers. The terpolymers are prepared by reacting a comonomermixture, the mixture having at least (1) a C₄ to C₈ isoolefin monomercomponent such as isobutylene, (2) a styrenic monomer, and (3) amultiolefin monomer component.

[0021] The terpolymer of the present invention can be defined by rangesof each monomer derived unit. The isoolefin is in a range from at least70 wt % by weight of the total terpolymer in one embodiment, and atleast 80 wt % in another embodiment, and at least 90 wt % in yet anotherembodiment, and from 70 wt % to 99.5 wt % in yet another embodiment, and85 to 99.5 wt % in another embodiment. The styrenic monomer is presentfrom 0.5 wt % to 30 wt % by weight of the total terpolymer in oneembodiment, and from 1 wt % to 25 wt % in another embodiment, and from 2wt % to 20 wt % in yet another embodiment, and from 5 wt % to 20 wt % inyet another embodiment. The multiolefin component in one embodiment ispresent in the terpolymer from 30 wt % to 0.2 wt % in one embodiment,and from 15 wt % to 0.5 wt % in another embodiment. In yet anotherembodiment, from 8 wt % to 0.5 wt % of the terpolymer is multiolefin.Desirable embodiments of terpolymer may include any combination of anyupper wt % limit combined with any lower wt % limit by weight of theterpolymer.

[0022] The isoolefin may be a C₄ to C₈ compound, in one embodimentselected from isobutylene, isobutene, 2-methyl-1-butene,3-methyl-1-butene, 2-methyl-2-butene, and 4-methyl-1-pentene. Thestyrenic monomer may be any substituted styrene monomer unit, anddesirably is selected from styrene, a-methylstyrene or an alkylstyrene(ortho, meta, or para), the alkyl selected from any C₁ to C₅ alkyl orbranched chain alkyl. In a desirable embodiment, the styrenic monomer isp-methylstyrene. The multiolefin may be a C₄ to C₁₄ diene, conjugated ornot, in one embodiment selected from isoprene, butadiene,2,3-dimethyl-1,3-butadiene, myrcene, 6,6-dimethyl-fulvene, hexadiene,cyclopentadiene, methylcyclopentadiene, and piperylene.

[0023] Isomonoolefin, styrene-based monomers, and multiolefin monomers,particularly isobutylene, p-methylstyrene and isoprene, can becopolymerized under cationic conditions. See, for example, WO 00/27807and 01/04731; U.S. Pat. No. 3,560,458, and U.S. Pat. No. 5,162,445. Thecopolymerization is carried out by means of at least one Lewis Acidcatalyst. Desirable catalysts are Lewis Acids based on metals from Group4, 13 and 15 of the Periodic Table of the Elements, including boron,aluminum, gallium, indium, titanium, zirconium, tin, vanadium, arsenic,antimony, and bismuth. In one embodiment, the metals are aluminum, boronand titanium, with aluminum being desirable.

[0024] The Group 13 Lewis Acids have the general formula R_(n)MX_(3−n),wherein “M” is a Group 13 metal, R is a monovalent hydrocarbon radicalselected from C₁ to C₁₂ alkyl, aryl, arylalkyl, alkylaryl and cycloalkylradicals; and n is an integer from 0 to 3; and X is a halogenindependently selected from fluorine, chlorine, bromine, and iodine,preferably chlorine. The term “arylalkyl” refers to a radical containingboth aliphatic and aromatic structures, the radical being at an alkylposition. The term “alkylaryl” refers to a radical containing bothaliphatic and aromatic structures, the radical being at an arylposition. Nonlimiting examples of these Lewis acids include aluminumchloride, aluminum bromide, boron trifluoride, boron trichloride, ethylaluminum dichloride (EtAlCl₂ or EADC), diethyl aluminum chloride(Et₂AlCl or DEAC), ethyl aluminum sesquichloride (Et_(1.5)AlCl_(1.5) orEASC), trimethyl aluminum, and triethyl aluminum.

[0025] The Group 4 Lewis Acids have the general formula MX₄, wherein Mis a Group 4 metal and X is a ligand, preferably a halogen. Nonlimitingexamples include titanium tetrachloride, zirconium tetrachloride, or tintetrachloride.

[0026] The Group 15 Lewis Acids have the general formula MX_(y), whereinM is a Group 15 metal, X is a ligand, preferably a halogen, and y is aninteger from 3 to 5. Nonlimiting examples include vanadium tetrachlorideand antimony pentafluoride. In one embodiment, Lewis acids may be any ofthose useful in cationic polymerization of isobutylene copolymersincluding: AlCl₃, EADC, EASC, DEAC, BF₃, TiCl₄, etc. with EASC and EADCbeing desirable in one embodiment.

[0027] Catalyst efficiency (based on Lewis Acid) in a large-scalecontinuous slurry reactor is preferably maintained between 10000 lb. ofpolymer/lb. of catalyst and 300 lb. of polymer/lb. of catalyst anddesirably in the range of 4000 lb. of polymer/lb. of catalyst to 1000lb. of polymer/lb. of catalyst by controlling the molar ratio of LewisAcid to initiator.

[0028] According to one embodiment of the invention, the Lewis Acidcatalyst is used in combination with an initiator. The initiator may bedescribed by the formula (A):

[0029] wherein X is a halogen, desirably chlorine or bromine; R₁ isselected from hydrogen, C₁ to C₈ alkyls, and C₂ to C₈ alkenyls, aryl,and substituted aryl; R₃ is selected from C₁ to C₈ alkyls, C₂ to C₈alkenyls, aryls, and substituted aryls; and R₂ is selected from C₄ toC₂₀₀ alkyls, C₂ to C₈ alkenyls, aryls, and substituted aryls, C₃ to C₁₀cycloalkyls, and groups represented by the following formula (B):

[0030] wherein X is a halogen, desirably chlorine or bromine; R₅ isselected from C₁ to C₈ alkyls, and C₂ to C₈ alkenyls; R₆ is selectedfrom C₁ to C₈ alkyls, C₂ to C₈ alkenyls aryls, and substituted aryls;and R₄ is selected from phenylene, biphenyl, α,ω-diphenylalkane and—(CH₂)_(n)—, wherein n is an integer from 1 to 10; and

[0031] wherein R₁, R₂, and R₃ can also form adamantyl or bornyl ringsystems, the X group being in a tertiary carbon position in oneembodiment.

[0032] As used herein, the term “alkenyl” refers to singly ormultiply-unsaturated alkyl groups such as, for example, C₃H₅ group, C₄H₅group, etc.

[0033] Substitution of the above structural formula radical (B) for R₂in formula (A) results in the following formula (C):

[0034] wherein X, R₁, R₃, R₄, R₅ and R₆ are as defined above. Thecompounds represented by structural formula (C) contain two dissociablehalides.

[0035] Multifunctional initiators are employed where the production ofbranched copolymers is desired, while mono- and di-functional initiatorsare preferred for the production of substantially linear copolymers.

[0036] In one desirable embodiment, the initiator is an oligomer ofisobutylene as represented in structure (D):

[0037] wherein X is a halogen, and the value of m is from 1 to 60, andmixtures thereof. In another embodiment, m is from 2 to 40. Thisstructure is also described as a tertiary alkyl chloride-terminatedpolyisobutylene having a Mn up to 2500 in one embodiment, and up to 1200in another embodiment.

[0038] Non-limiting examples of suitable initiators are cumyl esters ofhydrocarbon acids, and alkyl cumyl ethers, other cumyl compounds and orhalogenated organic compounds, especially secondary or tertiaryhalogenated compounds such as, for example, t-butyl chloride,2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy-2-phenyl propane(cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethylether)); the cumyl halides, particularly the chlorides, such as, forexample 2-chloro-2-phenylpropane, cumyl chloride (1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene(di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene(tri(cumylchloride)); the aliphatic halides, particularly the chlorides,such as, for example, 2-chloro-2,4,4-trimethylpentane (“TMPCl”),2-bromo-2,4,4-trimethylpentane (“TMPBr”), and2,6-dichloro-2,4,4,6-tetramethylheptane; cumyl and aliphatic hydroxylssuch as 1,4-di((2-hydroxyl-2-propyl)-benzene),2,6-dihydroxyl-2,4,4,6-tetramethyl-heptane, 1-chloroadamantane and1-chlorobornane, 5-tert-butyl-1,3-di(1-chloro-1-methyl ethyl) benzeneand similar compounds. Other suitable initiators are disclosed in U.S.Pat. Nos. 4,946,899, 3,560,458. These initiators are generally C₅ orgreater tertiary or allylic alkyl or benzylic halides and may includepolyfunctional initiators. Desirable examples of these initiatorsinclude: TMPCl, TMPBr, 2,6-dichloro-2,4,4,6-tetramethylheptane, cumylchloride as well as ‘di-’ and ‘tri-’ cumyl chloride or bromide.

[0039] The selected diluent or diluent mixture should provide a diluentmedium having some degree of polarity. To fulfil this requirement amixture of nonpolar and polar diluent can be used but one or a mixtureof polar diluents is preferred. Suitable nonpolar diluent componentsincludes hydrocarbons and preferably aromatic or cyclic hydrocarbons ormixtures thereof. Such compounds include, for instance,methylcyclohexane, cyclohexane, toluene, carbon disulfide and others.Appropriate polar diluents include halogenated hydrocarbons, normal,branched chain or cyclic hydrocarbons. Specific compounds include thepreferred liquid diluents such as ethyl chloride, methylene chloride,methylchloride (chloromethane), CHCl₃, CCl₄, n-butyl chloride,chlorobenzene, and other chlorinated hydrocarbons. To achieve suitablepolarity and solubility, it has been found that if the diluent, ordiluent mixture, is a mixture of polar and nonpolar diluents, themixture is preferably at least 70% polar component, on a volume basis.

[0040] The relative polarity of the diluent can be described in terms ofthe dielectric constant of the diluent. In one embodiment, the diluenthas a dielectric constant (as measured at from 20 to 25° C.) of greaterthan 5, and greater than 6 in another embodiment. In yet anotherembodiment, the dielectric constant of the diluent is greater than 7,and greater than 8 in yet another embodiment. In a desirable embodiment,the dielectric constant is greater than 9. Examples of dielectricconstants (20-25° C.) for single diluents are: chloromethane (10),dichloromethane (8.9), carbon disulfide (2.6), toluene (2.4), andcyclohexane (2.0) as from CRC HANDBOOK OF CHEMISTRY AND PHYSICS 6-151 to6-173 (D. R. Line, ed., 82 ed. CRC Press 2001).

[0041] As is typically the case, product molecular weights aredetermined by temperature, monomer and initiator concentration, thenature of the reactants, and similar factors. Consequently, differentreaction conditions will produce products of different molecular weightsand/or different monomer composition in the terpolymers. Synthesis ofthe desired reaction product will be achieved, therefore, throughmonitoring the course of the reaction by the examination of samplestaken periodically during the reaction, a technique widely employed inthe art and shown in the examples or by sampling the effluent of areactor.

[0042] The present invention is not herein limited by the method ofmaking the terpolymer. The terpolymer can be produced using batchpolymerization or continuous slurry polymerization, for example, and onany volume scale. The reactors that may be utilized in the practice ofthe present invention include any conventional reactors and equivalentsthereof. Preferred reactors include those capable of performing acontinuous slurry process, such as disclosed in U.S. Pat. No. 5,417,930.The reactor pump impeller can be of the up-pumping variety or thedown-pumping variety. The reactor will contain sufficient amounts of thecatalyst system of the present invention effective to catalyze thepolymerization of the monomer containing feed-stream such that asufficient amount of polymer having desired characteristics is produced.The feed-stream in one embodiment contains a total monomer concentrationgreater than 30 wt % (based on the total weight of the monomers,diluent, and catalyst system), greater than 35 wt % in anotherembodiment. In yet another embodiment, the feed-stream will contain from35 wt % to 50 wt % monomer concentration based on the total weight ofmonomer, diluent, and catalyst system. The bulk-phase, or phase in whichthe monomers and catalyst contact one another in order to react and forma polymer, may also have the same monomer concentrations.

[0043] The feed-stream or bulk-phase is substantially free from silicacation producing species in one embodiment of the invention. Bysubstantially free of silica cation producing species, it is meant thatthere is no more than 0.0005 wt % based on the total weight of themonomers of silica species in the feed stream or bulk-phase. Typicalexamples of silica cation producing species are halo-alkyl silicacompounds having the formula R₁R₂R₃SiX or R₁R₂SiX₂, etc., wherein each“R” is an alkyl and “X” is a halogen.

[0044] The reaction conditions are typically such that desirabletemperature, pressure and residence time are effective to maintain thereaction medium in the liquid state and to produce the desired polymershaving the desired characteristics. The monomer feed-stream is typicallysubstantially free of any impurity which is adversely reactive with thecatalyst under the polymerization conditions. For example, the monomerfeed preferably should be substantially free of bases (such as K₂O,NaOH, CaCO₃ and other hydroxides, oxides and carbonates),sulfur-containing compounds (such as H₂S, COS, and organo-mercaptans,e.g., methyl mercaptan, ethyl mercaptan), N-containing compounds, oxygencontaining bases such as alcohols and the like. By “substantially free”,it is meant that the above mentioned species are present, if at all, toan extent no greater than 0.0005 wt %.

[0045] In one embodiment, the ratio of monomers contacted together inthe presence of the catalyst system ranges from 98 wt % isoolefin, 1.5wt % styrenic monomer, and 0.5 wt % multiolefin (“98/1.5/0.5”), to a50/25/25 ratio by weight of the total amount of monomers. For example,the isoolefin monomer may be present from 50 wt % to 98 wt % by totalweight of the monomers in one embodiment, and from 70 wt % to 90 wt % inanother embodiment. The styrenic monomers may be present from 1.5 wt %to 25 wt % by total weight of the monomers in one embodiment, and from 5wt % to 15 wt % in another embodiment. The multiolefin may be presentfrom 0.5 wt % to 25 wt % by total weight of the monomers in oneembodiment, and from 2 wt % to 10 wt % in another embodiment, and from 3wt % to 5 wt % in yet another embodiment.

[0046] The polymerization reaction temperature is conveniently selectedbased on the target polymer molecular weight and the monomer to bepolymerized as well as standard process variable and economicconsiderations, for example, rate, temperature control, etc. Thetemperature for the polymerization is between −10° C. and the freezingpoint of the polymerization system in one embodiment, and from −25° C.to −120° C. in another embodiment. In yet another embodiment, thepolymerization temperature is from −40° C. to −100° C., and from −70° C.to −100° C. in yet another embodiment. In yet another desirableembodiment, the temperature range is from −80° C. to −99° C. Thetemperature is chosen such that the desired polymer molecular weight isachieved, the range of which may comprise any combination of any upperlimit and any lower limit disclosed herein.

[0047] The catalyst (Lewis Acid) to monomer ratio utilized are thoseconventional in this art for carbocationic polymerization processes.Particular monomer to catalyst ratios are desirable in continuous slurryor solution processes, wherein most any ratio is suitable for small,laboratory scale polymer synthesis. In one embodiment of the invention,the catalyst to monomer mole ratios will be from 0.10 to 20, and in therange of 0.5 to 10 in another embodiment. In yet another desirableembodiment, the ratio of Lewis Acid to initiator is from 0.75 to 2.5, orfrom 1.25 to 1.5 in yet another desirable embodiment. The overallconcentration of the initiator is from 50 to 300 ppm within the reactorin one embodiment, and from 100 to 250 ppm in another embodiment. Theconcentration of the initiator in the catalyst feed stream is from 500to 3000 ppm in one embodiment, and from 1000 to 2500 ppm in anotherembodiment. Another way to describe the amount of initiator in thereactor is by its amount relative to the polymer. In one embodiment,there is from 0.25 to 5.0 moles polymer/mole initiator, and from 0.5 to3.0 mole polymer/mole initiator in another embodiment.

[0048] It is known that chlorine or bromine can react with unsaturationof the multiolefin derived units (e.g., isoprene residue units) rapidlyto form halogenated polymer. Methods of halogenating polymers such asbutyl polymers are disclosed in U.S. Pat. No. 2,964,489; U.S. Pat. No.2,631,984; U.S. Pat. No. 3,099,644; U.S. Pat. No. 4,254,240; U.S. Pat.No. 4,554,326; U.S. Pat. No. 4,681,921; U.S. Pat. No. 4,650,831; U.S.Pat. No. 4,384,072; U.S. Pat. No. 4,513,116; and U.S. Pat. No.5,681,901. Typical halogenation processes for making halobutyl rubbersinvolves injection of a desirable amount of chlorine or bromine into thecement (solution) of butyl rubber with the reactants being mixedvigorously in the halogenation reactor with a rather short residenttime, typically less than 1 minute, following by neutralization of theHCl or HBr and any unreacted halogen. It is also well known in the artthat the specific structure of the halogenated butyl rubber iscomplicated and is believed to depend on the halogenation condition.Most commercial bromobutyl rubbers are made under the condition that theformation of “structure III” type brominated moiety is minimized, as isthe brominated terpolymer of the present invention. See, for example,Anthony Jay Dias in 5 POLYMERIC MATERIALS ENCYCLOPEDIA 3485-3492 (JosephC. Salamone, ed., CRC Press 1996). That typically means the absence offree radical sources such as light or high temperature. Alternativelythe halogenation can be carried out in polymer melt in an extruder orother rubber mixing devices in the absence of solvent.

[0049] The final level of halogen on the halogenated terpolymer,including halogen located on the polymer backbone and the styrenicmoieties incorporated therein, depends on the application and desirablecuring performance. The halogen content of a typical halogenatedterpolymer of the present invention ranges from 0.05 wt % to 5 wt % byweight of the terpolymer in one embodiment, and from 0.2 wt % to 3 wt %in another embodiment, and from 0.8 wt % to 2.5 wt % in yet anotherembodiment. In yet another embodiment, the amount of halogen present onthe terpolymer is less than 10 wt %, and less than 8 wt % in anotherembodiment, and less than 6 wt % in yet another embodiment. Statedanother way, the amount of halogen incorporated into the terpolymer isfrom less than 5 mole % in one embodiment, and from 0.1 to 2.5 mole %relative to the total moles of monomer derived units in the terpolymerin another embodiment, and from 0.2 to 2 mole % in another embodiment,and from 0.4 to 1.5 mole % in yet another embodiment. A desirable levelof halogenation may include any combination of any upper wt % or mole %limit with any lower wt % or mole % limit.

[0050] In another embodiment, the halogen content on the backbone(isoprene derived units) of a typical halogenated terpolymer of thepresent invention ranges from 0.05 wt % to 5 wt % by weight of theterpolymer in one embodiment, and from 0.2 wt % to 3 wt % in anotherembodiment, and from 0.8 wt % to 25 wt % in yet another embodiment. Inyet another embodiment, the amount of halogen present on the terpolymeris less than 10 wt %, and less than 8 wt % in another embodiment, andless than 6 wt % in yet another embodiment. Stated another way, theamount of halogen incorporated into the terpolymer is from less than 5mole % in one embodiment, and from 0.1 to 2.5 mole % relative to thetotal moles of monomer derived units in the terpolymer in anotherembodiment, and from 0.2 to 2 mole % in another embodiment, and from 0.4to 1.5 mole % in yet another embodiment. A desirable level ofhalogenation may include any combination of any upper wt % or mole %limit with any lower wt % or mole % limit.

[0051] In yet another embodiment, the halogen content on the styrenicmoieties, for example, p-methylstyrene (thus formingp-halomethylstyrene), was from 0.05 wt % to 5 wt %, and from 0.2 to 3 wt% in yet another embodiment, and from 0.2 wt % to 2 wt % in yet anotherembodiment, and from 0.2 wt % to1 wt % in yet another embodiment, andfrom 0.5 wt % to 2 wt % in yet another embodiment.

[0052] The molecular weight, number average molecular weight, etc. ofthe terpolymer depends upon the reaction conditions employed, such as,for example, the amount of multiolefin present in the monomer mixtureinitially, the ratios of Lewis Acid to initiator, reactor temperature,and other factors. The terpolymer of the present invention has a numberaverage molecular weight (Mn) of up to 1,000,000 in one embodiment, andup to 800,000 in another embodiment. In yet another embodiment, theterpolymer has an Mn of up to 400,000, and up to 300,000 in yet anotherembodiment, and up to 180,000 in yet another embodiment. The Mn value ofthe terpolymer is at least 80,000 in another embodiment, and at least100,000 in yet another embodiment, and at least 150,000 in yet anotherembodiment, and at least 300,000 in yet another embodiment. A desirablerange in the Mn value of the terpolymer can be any combination of anyupper limit and any lower limit.

[0053] The terpolymer has a weight average molecular weight (Mw) of upto 2,000,000 in one embodiment, and up to 1,000,000 in anotherembodiment, and up to 800,000 in yet another embodiment, and up to500,000 in yet another embodiment. The Mw value for the terpolymer is atleast 80,000 in yet another embodiment, and at least 100,000 in anotherembodiment, and at least 150,000 in yet another embodiment, and at least200,000 in yet another embodiment. The desirable range in the Mw valueof the terpolymer can be any combination of any upper limit and anylower limit.

[0054] The peak molecular weight value (Mp) of the terpolymer is atleast 2,000,000 in one embodiment, 100,000 another one embodiment, andat least 150,000 in another embodiment, and at least 300,000 in yetanother embodiment. The Mp value of the terpolymer is up to 600,000 inanother embodiment, and up to 400,000 in yet another embodiment. Thedesirable range in the Mp value of the terpolymer can be any combinationof any upper limit and any lower limit.

[0055] The terpolymer has a molecular weight distribution (Mw/Mn, orMWD) of less than 7.0 in one embodiment, and less than 4.0 in anotherembodiment, and from 1.5 to 3.8 in yet another embodiment. In yetanother embodiment, the MWD value is from 2.0 to 3.5. The value MWD canbe any combination of any upper limit value and any lower limit value.

[0056] Finally, the terpolymer of the invention has a Mooney viscosity(1+8, 100° C.) of from 20 to 60 MU in one embodiment, and from 25 to 55MU in another embodiment, and from 30 to 50 in yet another embodiment.

[0057] The terpolymer and/or halogenated terpolymer may be part of acomposition including other components such as one or more secondaryrubber components, a cure system, especially a sulfur cure system, atleast one filler such as carbon black or silica, and other minorcomponents common in the rubber compounding arts. The terpolymer orhalogenated terpolymer may be present from 5 phr to .100 phr in thecomposition one embodiment, from 20 phr to 100 phr in the composition inanother embodiment, and from 30 phr to 90 ph in yet another embodiment,and from 40 phr to 80 phr in yet another embodiment, and from 20 phr to50 phr in yet another embodiment, and from 15 phr to 55 phr in yetanother embodiment, and up to 100 phr in another embodiment.

Secondary Rubber Component

[0058] A secondary rubber component may be present in compositions ofthe present invention. These rubbers include, but are not limited to,natural rubbers, polyisoprene rubber, poly(styrene-co-butadiene) rubber(SBR), polybutadiene rubber (BR), poly(isoprene-co-butadiene) rubber(IBR), styrene-isoprene-butadiene rubber (SIBR), ethylene-propylenerubber (EPM), ethylene-propylene-diene rubber (EPDM), polysulfide,nitrile rubber, propylene oxide polymers, star-branched butyl rubber andhalogenated star-branched butyl rubber, brominated butyl rubber,chlorinated butyl rubber, star-branched butyl (polyisobutylene/isoprenecopolymer) rubber, star-branched halognated (preferably brominated orchlorinated) butyl (polyisobutylene/isoprene copolymer) rubber;poly(isobutylene-co-p-methylstyrene) and halogenatedpoly(isobutylene-co-p-methylstyrene), such as, for example, terpolymersof isobutylene derived units, p-methylstyrene derived units, andp-bromomethylstyrene derived units, and mixtures thereof.

[0059] A desirable embodiment of the secondary rubber component presentis natural rubber. Natural rubbers are described in detail bySubramaniam in RUBBER TECHNOLOGY 179-208 (Maurice Morton, Chapman & Hall1995). Desirable embodiments of the natural rubbers of the presentinvention are selected from Malaysian rubber such as SMR CV, SMR 5, SMR10, SMR 20, and SMR 50 and mixtures thereof, wherein the natural rubbershave a Mooney viscosity at 100° C. (ML 1+4) of from 30 to 120, morepreferably from 40 to 65. The Mooney viscosity test referred to hereinis in accordance with ASTM D- 1646.

[0060] Polybutadiene (BR) rubber is another desirable secondary rubberuseful in the composition of the invention. The Mooney viscosity of thepolybutadiene rubber as measured at 100° C. (ML 1+4) may range from 35to 70,from 40 to about 65 in another embodiment, and from 45 to 60 inyet another embodiment. Some commercial examples of these syntheticrubbers useful in the present invention are NATSYN™ (Goodyear ChemicalCompany), and BUDENE™ 1207 or BR 1207 (Goodyear Chemical Company). Adesirable rubber is high cis-polybutadiene (cis-BR). By“cis-polybutadiene” or “high cis-polybutadiene”, it is meant that1,4-cis polybutadiene is used, wherein the amount of cis component is atleast 95%. An example of high cis-polybutadiene commercial products usedin the composition BUDENE™ 1207.

[0061] Rubbers of ethylene and propylene derived units such as EPM andEPDM are also suitable as secondary rubbers. Examples of suitablecomonomers in making EPDM are ethylidene norbornene, 1,4-hexadiene,dicyclopentadiene, as well as others. These rubbers are described inRUBBER TECHNOLOGY 260-283 (1995). A suitable ethylene-propylene rubberis commercially available as VISTALON™ (ExxonMobil Chemical Company,Houston Tex.).

[0062] In another embodiment, the secondary rubber is a halogenatedrubber as part of the terpolymer composition. The halogenated butylrubber is brominated butyl rubber, and in another embodiment ischlorinated butyl rubber. General properties and processing ofhalogenated butyl rubbers is described in THE VANDERBILT RUBBER HANDBOOK105-122 (Robert F. Ohm ed., R. T. Vanderbilt Co., Inc. 1990), and inRUBBER TECHNOLOGY 311-321 (1995). Butyl rubbers, halogenated butylrubbers, and star-branched butyl rubbers are described by Edward Kresgeand H. C. Wang in 8 KIRK-OTHMER ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY934-955 (John Wiley & Sons, Inc. 4th ed. 1993).

[0063] The secondary rubber component of the present invention includes,but is not limited to at least one or more of brominated butyl rubber,chlorinated butyl rubber, star-branched butyl rubber, star-branchedhalogenated (preferably brominated or chlorinated) butyl(polyisobutylene/isoprene copolymer) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene), such as, for example, terpolymersof isobutylene derived units, p-methylstyrene derived units,- andp-bromomethylstyrene derived units (BrIBMS), and the like halomethylatedaromatic interpolymers as in U.S. Pat. No. 5,162,445; U.S. Pat. No.4,074,035; and U.S. Pat. No. 4,395,506; halogenated isoprene andhalogenated isobutylene copolymers, polychloroprene, and the like, andmixtures of any of the above. Some embodiments of the halogenated rubbercomponent are also described in U.S. Pat. No. 4,703,091 and U.S. Pat.No. 4,632,963.

[0064] In one embodiment of the invention, a so called semi-crystallinecopolymer (“SCC”) is present as the secondary “rubber” component.Semi-crystalline copolymers are described in WO00/69966. Generally, theSCC is a copolymer of ethylene or propylene derived units and α-olefinderived units, the α-olefin having from 4 to 16 carbon atoms in oneembodiment, and in another embodiment the SCC is a copolymer of ethylenederived units and α-olefin derived units, the α-olefin having from 4 to10 carbon atoms, wherein the SCC has some degree of crystallinity. In afurther embodiment, the SCC is a copolymer of 1-butene derived units andanother α-olefin derived unit, the other α-olefin having from 5 to 16carbon atoms, wherein the SCC also has some degree of crystallinity. TheSCC can also be a copolymer of ethylene and styrene.

[0065] The secondary rubber component of the elastomer composition maybe present in a range from up to 90 phr in one embodiment, from up to 50phr in another embodiment, from up to 40 phr in another embodiment, andfrom up to 30 phr in yet another embodiment. In yet another embodiment,the secondary rubber is present from at least 2 phr, and from at least 5phr in another embodiment, and from at least 5 phr in yet anotherembodiment, and from at least 10 phr in yet another embodiment. Adesirable embodiment may include any combination of any upper phr limitand any lower phr limit. For example, the secondary rubber, eitherindividually or as a blend of rubbers such as, for example NR and BR,may be present from 5 phr to 90 phr in one embodiment, and from 10 to 80phr in another embodiment, and from 30 to 70 phr in yet anotherembodiment, and from 40 to 60 phr in yet another embodiment, and from 5to 50 phr in yet another embodiment, and from 5 to 40 phr in yet anotherembodiment, and from 20 to 60 phr in yet another embodiment, and from 20to 50 phr in yet another embodiment, the chosen embodiment dependingupon the desired end use application of the composition.

Filler

[0066] Elastomeric compositions of the invention may include one or morefiller components such as calcium carbonate, clay, mica, silica andsilicates, talc, titanium dioxide, starch and other organic fillers suchas wood flower, and carbon black. In one embodiment, the filler iscarbon black or modified carbon black. In one embodiment, the filler isreinforcing grade carbon black present at a level of from 10 to 150 phrof the composition, more preferably from 30 to 120 phr. Useful grades ofcarbon black are described in RUBBER TECHNOLOGY 59-85 (1995) and rangefrom N110 to N990. More desirably, embodiments of the carbon blackuseful in, for example, tire treads are N229, N351, N339, N220, N234 andN110 provided in ASTM (D3037, D1510, and D3765). Embodiments of thecarbon black useful in, for example, sidewalls in tires, are N330, N351,N550, N650, N660, and N762. Embodiments of the carbon black useful in,for example, innerliners or innertubes are N550, N650, N660, N762, N990,and Regal 85 (Cabot Corporation Alpharetta, Ga.) and the like.

[0067] Exfoliated clays may also be present in the composition. Theseclays, also referred to as “nanoclays”, are well known, and theiridentity, methods of preparation and blending with polymers is disclosedin, for example, JP2000109635; JP2000109605; JP11310643; DE19726278;WO98/53000; U.S. Pat. No. 5,091,462; U.S. Pat. No. 4,431,755; U.S. Pat.No. 4,472,538; and U.S. Pat. No. 5,910,523. Swellable layered claymaterials suitable for the purposes of this invention include natural orsynthetic phyllosilicates, particularly smectic clays such asmontmorillonite, nontronite, beidellite, volkonskoite, laponite,hectorite, saponite, sauconite, magadite, kenyaite, stevensite and thelike, as well as vermiculite, halloysite, aluminate oxides, hydrotalciteand the like. These layered clays generally comprise particlescontaining a plurality of silicate platelets having a thickness of from4-20 Å in one embodiment, 8-12 Å in another embodiment, bound togetherand contain exchangeable cations such as Na⁺, Ca⁺², K⁺ or Mg⁺² presentat the interlayer surfaces.

[0068] The layered clay may be intercalated and exfoliated by treatmentwith organic molecules (swelling agents) capable of undergoing ionexchange reactions with the cations present at the interlayer surfacesof the layered silicate. Suitable swelling agents include cationicsurfactants such as ammonium, alkylamines or alkylammonium (primary,secondary, tertiary and quaternary), phosphonium or sulfoniumderivatives of aliphatic, aromatic or arylaliphatic amines, phosphinesand sulfides. Desirable amine compounds (or the corresponding ammoniumion) are those with the structure R₁R₂R₃N, wherein R₁, R₂, and R₃ are C₁to C₂₀ alkyls or alkenes which may be the same or different. In oneembodiment, the exfoliating agent is a long chain tertiary amine,wherein at least R₁ is a C₁₄ to C₂₀ alkyl or alkene.

[0069] Another class of swelling agents include those which can becovalently bonded to the interlayer surfaces. These include polysilanesof the structure —Si(R′)₂R² where R′ is the same or different at eachoccurrence and is selected from alkyl, alkoxy or oxysilane and R² is anorganic radical compatible or soluble with the matrix polymer of thecomposite.

[0070] Other suitable swelling agents include protonated amino acids andsalts thereof containing 2-30 carbon atoms such as 12-aminododecanoicacid, epsilon-caprolactam and like materials. Suitable swelling agentsand processes for intercalating layered silicates are disclosed in U.S.Pat. No. 4,472,538; U.S. Pat. No. 4,810,734; U.S. Pat. No. 4,889,885; aswell as WO92/02582.

[0071] In one embodiment of the invention, the exfoliating additive iscombined with the halogenated terpolymer. In one embodiment, theadditive includes all primary, secondary and tertiary amines andphosphines; alkyl and aryl sulfides and thiols; and their polyfunctionalversions. Desirable additives include: long-chain tertiary amines suchas N,N-dimethyl-octadecylamine, N,N-dioctadecyl-methylamine, so calleddihydrogenated tallowalkyl-methylamine and the like, andamine-terminated polytetrahydrofuran; long-chain thiol and thiosulfatecompounds like hexamethylene sodium thiosulfate. In another embodimentof the invention, improved interpolymer impermeability is achieved bythe presence of polyfunctional curatives such as hexamethylenebis(sodium thiosulfate) and hexamethylene bis(cinnamaldehyde).

[0072] In yet another embodiment of the composition, the filler may be amineral filler such as silica. A description of desirable mineralfillers is described by Walter H. Waddell and Larry R. Evans in RUBBERTECHNOLOGY, COMPOUNDING AND TESTING FOR PERFORMANCE 325-332 (John S.Dick, ed. Hanser Publishers 2001). Such mineral fillers include calciumcarbonate and other alkaline earth and alkali metal carbonates, bariumsulfate and other metal sulfates, ground crystalline silica, biogenicsilica, such as from dolomite, kaolin clay and other alumina-silicateclays, talc and other magnesium-silica compounds, alumina, metal oxidessuch as titanium oxide and other Group 3-12 metal oxides, any of whichnamed above can be precipitated by techniques known to those skilled inthe art. Particularly desirable mineral fillers include precipitatedsilicas and silicates. Other suitable non-black fillers and processingagents (e.g., coupling agents) for these fillers are disclosed in theBLUE BOOK 275-302, 405-410 (Lippincott & Peto Publications, RubberWorld2001).

[0073] When such mineral fillers are present, it is desirable to alsoinclude organosilane coupling agents. The coupling agent is typically abifunctional organosilane cross-linking agent. By an “silane couplingagent” is meant any silane coupled filler and/or cross-linking activatorand/or silane reinforcing agent known to those skilled in the artincluding, but not limited to, vinyl triethoxysilane,vinyl-tris-(beta-methoxyethoxy)silane,methacryloylpropyltrimethoxysilane, gamma-amino-propyl triethoxysilane(sold commercially as A1100 by Witco),gamma-mercaptopropyltrimethoxysilane (A189 by Witco) and the like, andmixtures thereof. In a preferred embodiment,bis-(3(triethoxysilyl)-propyl)-tetrasulfane (sold commercially as Si69by Degussa AG, Germany) is employed. Preferably, theorganosilane-coupling agent composes from 2 to 15 weight percent, basedon the weight of filler, of the elastomeric composition. Morepreferably, it composes from 4 to 12 weight percent of the filler.

[0074] The filler component of the elastomer composition may be presentin a range from up to 120 phr in one embodiment, from up to 100 phr inanother embodiment, and from up to 60 phr in yet another embodiment. Inyet another embodiment, the filler is present from 5 phr to 80 phr, from50 phr to 80 phr in yet another embodiment, from 20 phr to 80 phr in yetanother embodiment, from 10 phr to 70 phr in yet another embodiment,from 50 phr to 70 phr in yet another embodiment, and from 60 phr to 90phr in yet another embodiment, wherein a desirable range can by anycombination of any upper phr limit and any lower phr limit.

Curing Agents and Accelerators

[0075] The compositions produced in accordance with the presentinvention typically contain other components and additives customarilyused in rubber mixes, such as pigments, accelerators, cross-linking andcuring materials, antioxidants, antiozonants, and fillers.

[0076] Generally, polymer compositions, for example, those used toproduce tires, are crosslinked. It is known that the physicalproperties, performance characteristics, and durability of vulcanizedrubber compounds are directly related to the number (crosslink density)and type of crosslinks formed during the vulcanization reaction. (See,e.g., W. Helt et al., The Post Vulcanization Stabilization for NR,RUBBER WORLD 18-23 (1991). Cross-linking and curing agents includesulfur, zinc oxide, and fatty acids. Peroxide cure systems may also beused.

[0077] More particularly, in a desirable embodiment of the compositionof the invention, a “sulfur cure system” is present in the composition.The sulfur cure system of the present invention includes at least asulfur compound such as elemental sulfur, and may include sulfur-basedaccelerators. Generally, the terpolymer compositions may be crosslinkedby adding curative molecules, for example sulfur, metal oxides (e.g.,zinc oxide), organometallic compounds, radical initiators, etc. followedby heating. In particular, the following are common curatives that willfunction in the present invention: ZnO, CaO, MgO, Al₂O₃, CrO₃, FeO,Fe₂O₃, and NiO. These metal oxides can be used in conjunction with thecorresponding metal stearate complex (e.g., Zn(Stearate)₂,Ca(Stearate)₂, Mg(Stearate)₂, and Al(Stearate)₃), or with stearic acid,and either a sulfur compound or an alkylperoxide compound. (See also,Formulation Design and Curing Characteristics of NBR Mixes for Seals,RUBBER WORLD 25-30 (1993). This method may be accelerated and is oftenused for the vulcanization of elastomer compositions. The sulfur curesystem of the present invention includes at least sulfur, typicallyelemental sulfur, and may also include the metal oxides, acceleratorsand phenolic resins disclosed herein.

[0078] Accelerators include amines, guanidines, thioureas, thiazoles,thiurams, sulfenamides, sulfenimides, thiocarbamates, xanthates, and thelike. Acceleration of the cure process may be accomplished by adding tothe composition an amount of the accelerant. The mechanism foraccelerated vulcanization of natural rubber involves complexinteractions between the curative, accelerator, activators and polymers.Ideally, all of the available curative is consumed in the formation ofeffective crosslinks which join together two polymer chains and enhancethe overall strength of the polymer matrix. Numerous accelerators areknown in the art and include, but are not limited to, the following:stearic acid, diphenyl guanidine (DPG), tetramethylthiuram disulfide(TMTD), 4,4′-dithiodimorpholine (DTDM), tetrabutylthiuram disulfide(TBTD), 2,2′-benzothiazyl disulfide (MBTS),hexamethylene-1,6-bisthiosulfate disodium salt dihydrate,2-(morpholinothio) benzothiazole (MBS or MOR), compositions of 90% MORand 10% MBTS (MOR 90), N-tertiarybutyl-2-benzothiazole sulfenamide(TBBS), and N-oxydiethylene thiocarbamyl-N-oxydiethylene sulfonamide(OTOS), zinc 2-ethyl hexanoate (ZEH), N, N′-diethyl thiourea.

[0079] The compositions of the invention may also include processingoils and resins such as paraffinic, naphthenic or aliphatic resins andoils. Processing aids include, but are not limited to, plasticizers,tackifiers, extenders, chemical conditioners, homogenizing agents andpeptizers such as mercaptans, petroleum and vulcanized vegetable oils,waxes, resins, rosins, and the like. The aid is typically present from1to 70 phr in one embodiment, from 5 to 60 phr in another embodiment, andfrom 10 to 50 phr in yet another embodiment. Some commercial examples ofprocessing aids are SUNDEX™ (Sun Chemicals) and FLEXON™ (ExxonMobilChemical). Other suitable additives are described by Howard L. Stevensin RUBBER TECHNOLOGY 20-58 (1995), especially in Tables 2.15 and 2.18.

[0080] In one embodiment of the invention, at least one curing agent(s)is present from 0.2 to 15 phr, and from 0.5 to 10 phr in anotherembodiment, and from 2 phr to 8 phr in yet another embodiment. Curingagents include those components described above that facilitate orinfluence the cure of elastomers, such as metals, accelerators, sulfur,peroxides, and other agents common in the art.

Test Methods

[0081] Cure properties were measured using a MDR 2000 at the indicatedtemperature and 0.5 degree arc. Test specimens were cured at theindicated temperature, typically from 150° C. to 160° C., for a time (inminutes) corresponding to T90+ appropriate mold lag. When possible,standard ASTM tests were used to determine the cured compound physicalproperties. Stress/strain properties (tensile strength, elongation atbreak, modulus values, energy to break) were measured at roomtemperature using an Instron 4202 or Instron 4204. Shore A hardness wasmeasured at room temperature by using a Zwick Duromatic. Abrasion losswas determined at room temperature by weight difference by using anAPH-40 Abrasion Tester with rotating sample holder (5 N counter balance)and rotating drum. Weight losses were indexed to that of the standardDIN compound with lower losses indicative of a higher DIN abrasionresistance index. The weight losses can be measured with an error of±5%.

[0082] Temperature-dependent (−80° C. to 60° C.) dynamic properties (G*,G′, G″ and tangent delta) were obtained using a Rheometrics ARES. Arectangular torsion sample geometry was tested at 1 or 10 Hz and 2%strain. The temperature-dependent tangent delta curve (such as generatedin, e.g., FIG. 1) maximizes at a temperature affording information usedto predict tire performance. The tangent delta values are measured withan error of ±5%, while the temperature is measured with an error of ±2%.Values of G″ or tangent delta measured in the range from −10° C. to 10°C. in laboratory dynamic testing can be used as predictors of tire wettraction, while values of from −20° C. to −40° C. are used to predictwinter traction.

[0083] Gel permeation chromatography was used to determine molecularweight data for the terpolymers. The values of number average molecularweight (Mn), weight average molecular weight (Mw) and peak molecularweight (Mp) obtained have an error of ±20%. The techniques fordetermining the molecular weight and molecular weight distribution (MWD)are generally described in U.S. Pat. No. 4,540,753 to Cozewith et al.and references cited therein, and in Verstrate et al., 21 MACROMOLECULES3360 (1988). In a typical measurement, a 3-column set is operated at 30°C. The elution solvent used may be stabilized tetrahydrofuran (THF), or1,2,4-trichlorobenzene (TCB). The columns are calibrated usingpolystyrene standards of precisely known molecular weights. Acorrelation of polystyrene retention volume obtained from the standards,to the retention volume of the polymer tested yields the polymermolecular weight.

[0084]¹H- and decoupled ¹³C-NMR spectroscopic analyses were run ineither CDCl₃ or toluene-d₈ at ambient temperature using a field strengthof 250 MHz (¹³C-63 MHz) or in tetrachloroethane-d₂ at 120° C. using afield strength of 500 MHz (¹³C-125 MHz) depending upon the sample'ssolubility. Incorporation (mol %) of isobutylene and isoprene into theterpolymers of all examples was determined by comparison the integrationof the methyl proton resonances with those of the methylene protonresonances and resonances specific for the PMS.

[0085] Other test methods are summarized in Table 1.

EXAMPLES

[0086] The present invention, while not meant to be limiting by, may bebetter understood by reference to the following examples and Tables. Thefollowing symbols are used throughout this description to describerubber components of the invention: IBIMS {terpolymer;poly(isobutylene-co-p-methylstyrene-co-isoprene)}; BrIBIMS {(brominatedterpolymer; brominatedpoly(isobutylene-co-p-methylstyrene-co-isoprene)}; IBMS{poly(isobutylene-co-p-methylstyrene)}; BrIBMS {brominatedpoly(isobutylene-co-p-methylstyrene-co-p-bromomethylstyrene)}; SBB{brominated star branched butyl rubber}; BR {polybutadiene}; NR {naturalrubber}; and SBR {styrene-butadiene rubber}.

[0087] The synthesis of the terpolymer useful in the invention wascarried out in two sets of 6 sample batch runs, each set demonstratingthe use of two different initiators. Tertiary-butylchloride (t-BuCl) wasthe initiator used in runs A-F, data for which is shown in Table 3A, and2-chloro-2,4,4-trimethylpentane (TMCP1) was the initiator used in runsG-L shown in Table 3B.

[0088] TMPCl was synthesized via reaction of diisobutylene (120 ml) andSOCl₂ (thionyl chloride, 80 ml) in 1 liter methylene chloride solvent at−35° C. overnight. The reaction was quenched by adding 64 g NaOH (in 800ml water) to the reactor. The resulting crude TMPCl was washed withwater until neutral and dried over MgSO₄ overnight. The dried TMPCl wasthen distilled over calcium hydride under vacuum. The reagents usedwere: methylene chloride (CH₂Cl₂) (Fisher Scientific); Diisobutylene(Aldrich, 97% purity); thionyl chloride (Aldrich, 97% purity); NaOH(Fisher Scientific); calcium chloride (Aldrich, 95% purity); MgSO₄(Aldrich, 99% purity).

[0089] For the runs A-F, the batch experiments were 250 mL reactions inchloromethane at an initial temperature of −93° C. The initiator used inthe examples was t-butylchloride (Aldrich Chemical Co.) and the Lewisacid catalyst used was 25 wt % solution of EADC(ethylaluminumdichloride) in heptane. The t-butylchloride initiator andEADC catalyst were pre-mixed at 3/1 molar ratio in chloromethane anddiluted to a final total concentration of about 1 wt % solution inchloromethane.

[0090] The isobutylene used in the examples was dried by passing theisobutylene vapor through drying columns, and then condensed in a cleanflask in a dry box prior to use. The p-methylstyrene and isoprenemonomers used in the examples were distilled under vacuum to removemoisture and free radical inhibitor prior to use. The monomer feed blendused in the terpolymer synthesis of runs A-F was a 10 wt % totalmonomers in chloromethane with 80/10/10 wt % ratio ofisobutylene/isoprene/p-methylstyrene.

[0091] The terpolymerization experiments were carried out in 500 mlglass reactors in a standard nitrogen atmosphere enclosure box (dry box)equipped with a cooling bath for low temperature reactions. Eachpolymerization batch used 250 ml of the monomer feed blend contained80/10/10 wt % ratio of isobutylene/isoprene/p-methylstyrene at 10 wt %total monomers in chloromethane. After the monomer solution was cooleddown to desired reaction temperature (<−90° C.), the pre-chilledinitiator/catalyst mixture solution was added slowly to the reactor toinitiate the polymerization. The rate of catalyst solution addition wascontrolled to avoid excessive temperature buildup in the reactor. Thus,catalyst was added incrementally to the bulk-phase within the reactor.The amount of total catalyst solution added was adjusted based on, amongother factors, the accumulated temperature increases that correlateswith amount of monomers consumed in the reactor. When desirable monomerconversion was reached (e.g., at least 50% conversion), a small amountof methanol was added to the reactor to quench the polymerizationreactions. The terpolymer was then isolated and dried in a vacuum ovenfor analysis.

[0092] The molecular weight and molecular weight distribution (Mw/Mn) ofthe resultant terpolymers were analyzed by standard Gel PermeationChromatography (GPC) techniques known in the art (described above). TheGPC analysis results of the terpolymers are shown in Table 3. The mole %ratios of monomer derived units in the final terpolymers obtained bystandard proton NMR technique are also shown in Table 3A. The compositeamount of unsaturated groups (also corresponding to the level ofisoprene {IP}) in the terpolymer of runs A-F is 4.14 mole %. Thecomposite amount of PMS in the final terpolymer of runs A-F is 4.64 mole%.

[0093] Bromination of the A-F terpolymer composite was carried out instandard round bottomed flasks using 5 wt % terpolymer solution incyclohexane. In order to minimize free radical bromination, the reactorwas completely shielded from light and a small amount (about 200 ppmbased on polymer charge) of BHT free radical inhibitor was added in thepolymer solution. A 10 wt % bromine solution in cyclohexane was preparedand transferred into a graduated addition funnel attached to thereactor. Desired amount of the bromine solution was then added dropwiseinto the terpolymer solution with vigorous agitation. The brominationreaction was quenched with excessive caustic solution 2-5 minutes afterthe bromine addition was completed. The excess caustic in theneutralized terpolymer solution was then washed with fresh water inseparatory funnel several times. The brominated terpolymer was isolatedby solvent precipitation in methanol and then dried in vacuum oven atmoderate temperature overnight.

[0094] Bromination resulted mostly in bromination of the unsaturation inthe backbone of the terpolymer, with some bromination of the PMS. Thelevel of bromine in the composite sample on the backbone is 0.80 mole %,and 0.06 mole % on the PMS as determined by NMR. The composite samplewas then subjected to a second bromination similar to above, resultingin a composite backbone bromine level of 1.19 mole %, a PMS brominelevel of 0.41 mole %, and a total bromination level of 1.68 mole %(±10%). This composite sample was used in the cure and compositionstudies to follow.

[0095] For the runs G-L, the batch experiments were 200 mL runs inchloromethane at an initial temperature of −93° C. Other conditions weresimilar to that for runs A-F. The catalyst solution in chloromethane hada ratio of EADC:TMPCl of 2 (by mole), and the monomer feed ratio was85/5/10 wt % ratio of isobutylene/isoprene/p-methylstyrene at 10 wt %total monomers in chloromethane. The batch polymerization processes ofruns G-L demonstrate the useful of using halogenated organic compounds,especially secondary or tertiary halogenated compounds described instructures (A) through (D) above, as initiators in the production ofbutyl-type rubbers, and especially butyl-type terpolymers such as IBIMS.

[0096] In demonstrating the cure characteristics of the IBIMS, the A-Fcomposite, and other comparative compounds, were mixed in two stagesusing a Haake Rheomix™ 600 internal mixer. Elastomers, fillers, andprocessing oil were mixed in the first step. The second step consistedof mixing the first step masterbatch and adding all other chemicalingredients. Mixing continued for three minutes or until a temperatureof 110° C. was reached. An open two-roll mill was used to sheet out thestocks after each Haake mixing step.

[0097] Examples of the compositions used to study the curecharacteristics of the terpolymer are found in Table 4, the propertiesof which are summarized in Tables 5A and 5B. Samples 1-9 represent theterpolymer in comparison with other known rubbers. Each sample 1-9includes 75 phr carbon black, N234; 30 phr SUNDEX™; 1.5 phr SANTOFLEX™;1 phr Agerite Resin D; 2 phr zinc oxide; 1 phr stearic acid; and 1.2 phrTBBS. The BrIBMS is EXXPRO™ 90-10, and the IBMS is from ExxonMobilChemical Company, a copolymer having the same backbone structure as theEXXPRO™ 90-10, without the p-bromomethylstyrene derived units. Thesamples were cured by heating to 160° C. for a time in minutescorresponding to T90+5 minutes. Compounds 3-7 did not cure. Theproperties of compounds 1, 2, 8 and 9 were tested, the results of whichare in Tables 5A and 5B.

[0098] It was demonstrated that sulfur, in the presence of other cureagents, effectively cures the terpolymer IBIMS. Further, it was foundthat the abrasion resistance, as measured by the ARI, improves for IBIMSwhen a brominated phenolic resin, in the present case SP-1055, is addedas part of a cure system (Sample 8). On the other hand, the IBIMS, aswell as the IBMS, did not cure effectively without the presence ofsulfur (Samples 3-7). The comparison of the two polymers suggests thatthe presence of backbone unsaturation provided by the isoprene derivedunits is advantageous for vulcanization.

[0099] The usefulness of the BrIBIMS terpolymer of the invention invarious compositions is demonstrated in examples 10-16, Table 6. Here,various elastomers were combined with carbon black, cure agents, BR, andNR to simulate formulations that could be suitable, for example, fortire treads and sidewalls. Each of examples 10-16 also includes 75 phrcarbon black, N234; 30 phr SUNDEX™; 1.5 phr SANTOFLEX™; 1 phr AgeriteResin D; 2 phr zinc oxide; 1 phr stearic acid; 0.8 phr sulfur; and 1.2phr TBBS. The BrIBMS is EXXPRO™ 90-10, and the IBMS from ExxonMobilChemical Company, Houston Tex. The samples were blended and cured at160° C. as described above. The samples 10-16 were tested and theirvarious properties are outlined in Tables 7A and 7B.

[0100] These examples indicate that compositions of the BrIBIMS haveimproved abrasion resistance and traction relative to, for example,BrIBMS, and approaching that of SBR. More specifically, referring to theabrasion ARI values for each of the sample compositions, it is apparentthat sample 12 shows the highest value other than the SBR composition ofexample 16, which is known to have relatively high abrasion resistance.The ARI values for the brominated terpolymer compositions of theinvention are an improvement over the other elastomers tested. In oneembodiment, the abrasion resistance of the halogenated terpolymerincluding at least carbon black is greater than 90 units, and greaterthan 95 units in another embodiment, and greater than 100 units in yetanother embodiment.

[0101] Surprisingly, along with the improved abrasion values for thebrominated terpolymer composition was an improved traction as measuredby the tangent delta. These values are exemplified in Table 8, and inFIG. 1. In particular, the halogenated terpolymer compositions withcarbon black show potentially improved winter and wet traction asindicated by the higher tangent delta values from −40° C. to 10° C. Inone embodiment, the halogenated terpolymer compositions including carbonblack as the filler have a tangent delta value of from greater than 0.50at −30° C., and from greater than 0.55 at −30° C. in another embodiment,and from greater than 0.60 at −30° C. in yet another embodiment,exemplifying improved winter traction. In another embodiment of thecomposition of the invention, the tangent delta values are from greaterthan 0.38 at 0° C., and from greater than 0.40 at 0° C. in anotherembodiment, and from greater than 0.42 at 0° C. in yet anotherembodiment, exemplifying improved wet traction. These results indicatethat compositions of the halogenated, and in particular, brominatedterpolymer and other elastomeric components are suitable for automotivetire components, in particular, sidewalls and/or treads.

[0102] Compositions of the terpolymer (BrIBIMS) with silica were alsostudied, the compositions outlined in Table 9, and the test resultsoutlined in Tables 10A and 10B. These studies show that silica and acoupling agent can be used in a composition with the terpolymer, andthat a silica/coupling agent/carbon black blend (sample 19) showed themost desirable physical characteristics relative to the sample 17 and 18with silica and coupling agent only. The X50-S agent is a 1:1 blend, insolid form, of bis-(3-triethoxysilylpropyl) tetrasulfide:N330 carbonblack. The bis-(3-triethoxysilylpropyl) tetrasulfide is otherwise knownas “Si69”. The presence of this agent in the 50/50 wt % carbonblack/silica blend of sample 19 shows improved abrasion and elongationrelative to the samples 17 and 18 without the carbon black. Thus,compositions suitable for tire treads including silica and theterpolymer of the invention are also practical.

[0103] In one embodiment of the invention, the composition includes asilica filler with a silane coupling agent. In yet another embodiment,the composition includes a blend of carbon black and silica with asilane coupling agent, wherein the blend can range from 10 wt % to 90 wt% carbon black by weight of the carbon black and silica blend in oneembodiment, and from 20 wt % to 80 wt % carbon black in anotherembodiment, and from 30 wt % to 70 wt % carbon black in yet anotherembodiment, and from 40 wt % to 60 wt % carbon black in yet anotherembodiment, and 50 wt % carbon black in yet another embodiment. It isalso advantageous to include an agent such as X50-S from 2 to 10 phr ofthe entire composition.

[0104] The elastomeric compositions of the present invention may be usedfor the production of tires and tire components such as treads for anytype of rubber tires, for example, motor vehicle tires, such aspassenger automobile tires, truck tires, motorcycle tires, and the like.The tires typically comprise an outer surface having a tread portion andsidewalls. The composition of the present invention may be used toproduce at least a part of the tread portion or sidewall. The tire,including the tread portion, may be produced by any conventional method.The elastomeric composition described herein are also useful for anyapplication where high damping and/or high abrasion resistance isdesired such as in bicycle tires, vibration mounts, shoe soles, hoses,belts, windshield wipers, and other engineered elastomeric articles.

[0105] For example, one embodiment of the invention is a tire includinga tread and a sidewall made from blending the terpolymer, naturalrubber, polybutadiene rubber, carbon black and a sulfur cure agent indesirable quantities as described above. In particular, the BrIBIMS maybe present from 10 to 50 phr in the tread composition, natural rubbermay be present from 5 to 50 phr of the tread composition, andpolybutadiene rubber may be present from 10 to 60 phr of the treadcomposition, while a filler such as carbon black or carbon black/silicablends, or silica may be present from 30 to 100 phr of the composition.The tread may also include other components such as a sulfur curesystem, processing oils and accelerators, etc.

[0106] Another embodiment of the invention includes a tread or sidewallmade from blending the terpolymer, natural rubber, polybutadiene rubber,carbon black and a sulfur cure agent in as follows: BrIBIMS may bepresent from 25 to 45 phr in the tread composition, natural rubber maybe present from 10 to 30 phr of the tread composition, and polybutadienerubber may be present from 30 to 60 phr of the tread composition, whilea filler such as carbon black may be present from 50 to 75 phr of thecomposition. The tread may also include other components such as asulfur cure system, processing oils and accelerators, etc.

[0107] While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to many differentvariations not illustrated herein. For these reasons, then, referenceshould be made solely to the appended claims for purposes of determiningthe true scope of the present invention.

[0108] All priority documents are herein fully incorporated by referencefor all jurisdictions in which such incorporation is permitted. Further,all documents cited herein, including testing procedures, are hereinfully incorporated by reference for all jurisdictions in which suchincorporation is permitted. TABLE 1 Test Methods Parameter Units TestMooney Viscosity (BIMS polymer) ML 1 + 8, 125° C., MU ASTM D 1646(modified) Mooney Viscosity (composition) ML 1 + 4, 100° C., MU ASTM D1646 Brittleness ° C. ASTM D 746 Green Strength (100% Modulus) PSI ASTMD 412 Mooney Scorch Time T_(s)5, 125° C., minutes ASTM D 1646Oscillating Disk Rheometer (MDR) @ 160° C., ± 0.5°arc ML dNewton · m MHdNewton · m T_(s)2 minute T_(c)90 minute Cure rate dN · m/minute ASTM D2084 Physical Properties press cured Tc 90 + 2 min @ 160° C. HardnessShore A ASTM D 2240 Modulus MPa ASTM D 412-68 Tensile Strength MPaElongation at Break % Rebound — Zwick 5901.01 Rebound Tester ASTM D1054or ISO 4662 or DIN 53512 Dispersion D scale — DisperGrader 1000(Optigrade, Sweden) Abrasion Resistance (ARI) — ISO 4649 or DIN 53516Energy N/mm Area under the Elongation at break curve. Tangent Delta —Rheometrics ARES

[0109] TABLE 2 Components and Commercial Sources Component BriefDescription Commercial Source AgeRite ™ Resin D antioxidant, polymerized1,2- R.T. Vanderbilt (Norwalk, CT) dihydro-2,24- trimethylquinolineBromobutyl ™ 2222 brominated Poly(isobutylene- ExxonMobil Chemicalco-isoprene); Mooney Company (Houston, TX) Viscosity (1 + 8, 125° C.) offrom 27-37 MU; 2 wt % Br Budene ™ 1207 polybutadiene Goodyear (Akron,OH) Butyl ™ 365 poly(isobutylene-co-isoprene), ExxonMobil ChemicalMooney viscosity of 43-51 Company (Houston, TX) MU (1 + 8, 125° C.) EADCethyl aluminum dichloride AKZO Nobel Chemical EXXPRO ™ 90-10 7.5 wt %PMS, 1.2 mol % ExxonMobil Chemical BrPMS, Mooney viscosity of Company(Houston, TX) 45 ± 5 MU (1 + 8, 125° C.) isobutylene monomer ExxonMobilChemical Company (Houston, TX) isoprene monomer Aldrich Chemical Companynatural rubber, SMR 20 naturally occurring polymer of Herman Webber &CO. cis-polyisoprene (Redbank, New Jersey) p-methylstyrene (PMS) monomerAldrich Chemical Company SANTOFLEX ™ 13 antiozonate Flexsys America L.P.(Akron, OH) SP-1055 brominated phenol- Schenectady Internationalformaldehyde resin (Schenectady, NY) SBB star-branched butyl rubberExxonMobil Chemical 6222; 2 wt % Br Company (Houston, TX) SBR, NSI16styrene butadiene rubber, 20 Zeon Corporation (Japan) wt % styrene, 45Mooney viscosity silica, ZEOSIL ™ 1165 MP amorphous precipitated silicaRhodia, Inc. (Cranbury, NJ) stearic acid cure agent e.g., C.K. WitcoCorp. (Taft, LA) sulfur cure agent e.g., R.E. Carroll (Trenton, NJ)SUNDEX ™ 8125 processing oil, aromatic, ASTM Sun Chemical Co.(Cincinnati, 101 OH) TBBS cure agent, N-tertiarybutyl-2- Flexsys AmericaL.P. (Akron, benzothiazole sulfenamide OH) TMPCl 2-chloro-2,4,4- Seetext trimethylpentane IBMS copolymer of isobutylene and ExxonMobilChemical p-methylstyrene Company (Houston, TX) X50-S Si69, 50 wt %carbon black Degussa AG (Germany) blend zinc oxide, KADOX ™ 930 C cureagent, ZnO Zinc Corp. of America (Monaca, PA)

[0110] TABLE 3A Reaction conditions and results for runs A-F to produceterpolymer using t-butylchloride as the initiator. Composite condition AB C D E F (A-F) Moles monomer 0.390 0.390 0.390 0.390 0.390 0.390 —Volume Catalyst 48.0 66.0 75.5 50.0 51.5 65.5 — solution added (mL)†Change in 9.9 9.7 8.8 9.6 9.1 9.8 — temperature, ° C. Reaction time(min) 20.8 20.8 20.5 18.0 15.0 17.5 — % conversion 64.72 68.40 69.2461.64 58.68 59.68 — Mn 91,600 82,800 75,100 94,100 93,400 82,300 — Mw250,500 239,000 241,800 246,500 241,700 247,100 — Mp — 162,200 145,700168,900 175,900 158,900 — Mw/Mn 2.73 2.89 3.22 2.62 2.59 3.00 — Mole %unsaturated — — — — — — 4.14 groups (IP), H¹ NMR mole % PMS in — — — — —— 4.64 interpolymer, H¹ NMR

[0111] TABLE 3B Reaction conditions and results for runs G-L to produceterpolymer using TMPCl as the initiator. condition G H I J K L Moles PMSfeed 5.06 5.06 5.06 5.06 5.06 5.06 Moles isoprene feed 4.39 4.39 4.394.39 4.39 4.39 Volume Catalyst 35.0 20.0 15.0 30.0 40.0 25.0 solutionadded (mL)† Monomer/initiator 2876 5032 6710 3355 2516 4026 Change in11.0 6.9 6.1 11.2 10.7 7.7 temperature, ° C. Reaction time (min) 106.814.4 10.8 12.0 33.6 21.6 % conversion 50.73 31.63 19.43 45.93 50.2028.77 Mn 199,200 209,300 185,300 151,600 164,300 194,700 Mw 498,900538,200 532,000 482,900 536,600 527,200 Mp 374,000 380,000 424,000386,000 351,200 404,700 Mw/Mn 2.50 2.57 2.87 3.19 3.27 2.71 Mole %unsaturated 1.85 — 1.91 — — — groups (IP), H¹ NMR mole % PMS in 3.94 —3.92 — — — interpolymer, H¹ NMR

[0112] TABLE 4 Components of cure examples¹ Component (phr) 1 2 3 4 5 67 8 9 BrIBMS² 100 100 — — — — — — — IBMS — — 100 100 100 100 — — — IBIMS— — — — — — 100 100 100 sulfur — 0.8 — — 0.8 0.8 — 0.8 0.8 SP-1055 — — —3 — 3 — 3 —

[0113] TABLE 5A Properties of cure examples property 1 2 3 4 5 6 7 8 9MDR 160° C., 0.5 Arc: ML, dN · m 8.24 7.89 2.79 2.15 2.81 2.25 1.61 1.531.75 MH, dN · m 21.91 18.62 2.80 2.31 3.08 2.48 1.63 6.59 9.69 MH − ML,dN · m 13.67 11.23 0.01 0.17 0.27 0.24 0.02 5.06 7.94 Ts2, min 0.47 0.930 0 0 0 0 9.75 6.4 T25, min 0.8 1.16 29.49 1.09 2.05 5.38 29.3 7.1 6.37T50, min 1.8 2.21 29.49 3.31 4.09 10.68 29.3 12 9.28 T75, min 3.32 3.629.49 7.13 7.58 17.89 29.3 18.95 13.91 T90, min 5.09 5.28 29.49 14.4212.46 22.09 29.3 24.64 18.87 T95, min 6.32 6.57 29.49 18.58 14.17 24.8329.3 27.04 21.68 Rate, dN · m/min 17.9 4.0 0.1 0.2 0.2 0.2 0 0.5 1.2

[0114] TABLE 5B Properties of cure examples property 1 2 3* 4* 5* 6* 7*8 9  20% Modulus 1.12 1.13 — — — — — 0.71 0.69 100% Modulus 6.01 6.13 —— — — — 0.88 1.12 200% Modulus 12.88 12.91 — — — — — 1.20 2.02 300%Modulus — — — — — — — 1.75 3.30 Tensile 13.92 14.44 — — — — — 6.35 9.59Elongation 224 242 — — — — — 893 788 Energy 5.23 6.00 — — — — — 8.0611.31 Shore A Hardness at 23° C. 65.3 59.3 — — — — — 49.1 54.3 DINAbrasion Index 71 68 — — — — — 57 45 Dispersion D scale 9.4 9.1 — — — —— 9.1 7.8 Rebound %, 100° C. 44 44.4 — — — — — 30 30.1 Rebound %, 25° C.22.1 21.9 — — — — — 13.9 22.1

[0115] TABLE 6 Components in composition examples¹ Component (phr) 10 1112 13 14 15 16 BrIBMS² 40 — — — — — — IBMS — 40 — — — — — BrIBIMS — — 40— — — — IBIMS — — — 40 — — — SBB 6222 — — — — 40 — — Butyl 365 — — — — —40 — SBR — — — — — — 40 cis-BR 40 40 40 40 40 40 40 NR 20 20 20 20 20 2020

[0116] TABLE 7A Properties of composition examples Property 10 11 12 1314 15 16 MDR 160° C., 0.5° arc ML, dN · m 5.55 5.29 4.8 4.55 4.73 4.94.27 MH, dN · m 17.17 14.78 13.1 13.74 13.98 14.27 13.61 MH − ML, 11.629.49 8.3 9.19 9.26 9.37 9.35 dN · m Ts2, min 3.13 4.03 4.37 4.06 4.384.13 4.91 T25, min 3.7 4.15 4.43 4.16 4.54 4.25 5.09 T50, min 4.68 4.726.59 4.71 5.48 4.86 6.04 T75, min 6.09 5.42 10.75 5.39 6.75 5.6 7.31T90, min 8.17 6.29 16.85 6.24 8.5 6.5 9.07 T95, min 9.71 6.89 21.08 6.829.75 7.13 10.41 Rate, dN · m/min 3.3 4.5 1.1 4.4 2.6 4.2 2.5

[0117] TABLE 7B Properties of composition examples Property 10 11 12 1314 15 16  20% Modulus 0.81 0.77 0.81 0.73 0.79 0.74 0.75 100% Modulus2.32 1.80 1.73 1.62 1.63 1.64 1.44 200% Modulus 5.80 4.20 3.63 3.74 3.523.78 2.83 300% Modulus 10.29 7.38 6.58 6.82 6.48 6.83 5.32 Tensile 16.2212.03 12.45 11.65 14.04 11.29 14.93 Elongation 459 491 528 495 598 479678 Energy 10.58 8.42 9.45 8.25 11.83 7.60 14.05 Shore A Hardness at58.3 53.7 55.9 54.7 55.9 53.1 54.5 23° C. DIN Abrasion Index 96 79 10474 96 73 125 Dispersion D scale 8.6 8.9 8.2 8.8 7.8 7.3 8 Rebound %,100° C. 44.2 43.4 40.4 42.5 41.4 42.7 41.9 Rebound %, 25° C. 31.6 32.631.7 32.8 33.3 34.6 41

[0118] TABLE 8 Representative Tangent Delta values for the elastomers inFIG. 1 Tan Delta values at given temperatures, ° C. BrIBIMS BrIBMS SBBSBR 10 0.397 0.315 0.369 0.326 0 0.420 0.364 0.379 0.343 −10 0.472 0.4380.412 0.359 −20 0.570 0.546 0.476 0.379 −30 0.651 0.637 0.576 0.429 −400.567 0.594 0.679 0.532

[0119] TABLE 9 Components in silica composition examples¹ Component 1718 19 BrIBMS² 40 — — BrIBIMS — 40 40 NR 20 20 20 cis-BR 40 40 40 silica(ZEOSIL ™ 1165 MP) 75 75 37.5 carbon black (N234) — — 37.5 X50-S  9  94.5

[0120] TABLE 10A Properties of silica composition examples Property 1718 19 MDR 2 160° C., 0.5° Arc, ML, 8.56 6.73 6.04 dN · m MH, dN · m16.08 14.41 13.21 MH-ML, dN · m 7.52 7.68 7.17 Ts2, min 1.06 0.52 0.55T25, min 0.94 0.47 0.44 T50, min 4.29 2.87 2.74 T75, min 12.81 10.5310.51 T90, min 21.43 19.49 19.64 T95, min 25.36 24.04 24.31 Rate, dN ·m/min 8.56 6.73 6.04

[0121] TABLE 10B Properties of silica composition examples Property 1718 19  20% Modulus 0.84 0.78 0.73 100% Modulus 2.20 1.59 1.41 200%Modulus 4.96 3.10 2.52 300% Modulus ‡ 4.97 3.82 Tensile 7.12 5.65 4.81Elongation 273 343 386 Energy 2.56 2.88 2.90 Shore A Hardness at 23° C.59.5 54.3 55.1 DIN Abrasion Index 78 69 88 Dispersion D scale 6.1 5.25.3 Rebound %, 100° C. 55.3 46.4 46.6 Rebound %, 25° C. 37.8 34.2 34.8

We claim:
 1. An elastomeric composition comprising a filler; a sulfurcure system; at least one secondary rubber; and at least one terpolymerof C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derivedunits, and p-alkylstyrene derived units.
 2. The elastomeric compositionof claim 1, wherein the cure system includes at least one metal oxide,elemental sulfur, and optionally at least one accelerator.
 3. Theelastomeric composition of claim 1, wherein the filler is selected fromcarbon black, silica, alumina, calcium carbonate, clay, mica, talc,titanium dioxide, starch, wood flower, and mixtures thereof.
 4. Theelastomeric composition of claim 1, wherein the secondary rubber isselected from natural rubber, polybutadiene rubber, and mixturesthereof.
 5. The elastomeric composition of claim 1, wherein thesecondary rubber is selected from nitrile rubber, silicon rubber,polyisoprene rubber, poly(styrene-co-butadiene) rubber,poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched butyl rubber, star-branched halogenated(preferably brominated or chlorinated) butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 6. Theelastomeric composition of claim 1, wherein the C₄ to C₈ isoolefinmonomer is isobutylene.
 7. The elastomeric composition of claim 1,wherein the C₄ to C₁₄ multiolefin monomer is isoprene.
 8. Theelastomeric composition of claim 1, wherein the p-alkylstyrene isp-methylstyrene.
 9. The elastomeric composition of claim 1, wherein theterpolymer is halogenated.
 10. The elastomeric composition of claim 9,wherein the halogen is present in the terpolymer in the range of from0.1 mole % to 2.5 mole % based on the total moles of monomer derivedunits in the terpolymer.
 11. The elastomeric composition of claim 9,wherein the halogen is present in the terpolymer in the range of from0.2 mole % to 2 mole % based on the total moles of monomer derived unitsin the terpolymer.
 12. The elastomeric composition of claim 9, whereinthe terpolymer is brominated.
 13. The elastomeric composition of claim1, wherein the secondary rubber is present from 5 to 90 phr.
 14. Theelastomeric composition of claim 1, wherein the terpolymer is presentfrom 10 to 100 phr.
 15. The elastomeric composition of claim 1, whereinthe filler is carbon black, and the terpolymer is halogenated.
 16. Theelastomeric composition of claim 15, having a DIN Abrasion Index of atleast 90 units.
 17. The elastomeric composition of claim 15, having atangent delta value of at least 0.50 at −30° C.
 18. The elastomericcomposition of claim 15, having a tangent delta value of at least 0.38at 0° C.
 19. The elastomeric composition of claim 1, wherein the filleris from 5 to 100 phr.
 20. The elastomeric composition of claim 1,wherein the filler is a blend of carbon black and silica.
 21. A tirecomprising the composition of claim
 9. 22. A tread or sidewallcomprising the composition of claim
 9. 23. A method of producing anelastomeric terpolymer composition comprising combining, in a diluent,C₄ to C₈ isoolefin monomers, C₄ to C₁₄ multiolefin monomers, andp-alkylstyrene monomers in the presence of a Lewis acid and at least oneinitiator to produce the terpolymer.
 24. The method of claim 23, whereinthe initiator is described by the following formula:

wherein X is a halogen; R₁ is selected from hydrogen, C₁ to C₈ alkyls,and C₂ to C₈ alkenyls, aryl, and substituted aryl; R₃ is selected fromC₁ to C₈ alkyls, C₂ to C₈ alkenyls, aryls, and substituted aryls; and R₂is selected from C₄ to C₂₀₀ alkyls, C₂ to C₈ alkenyls, aryls, andsubstituted aryls, C₃ to C₁₀ cycloalkyls, and

wherein X is a halogen; R₅ is selected from C₁, to C₈ alkyls, and C₂ toC₈ alkenyls; R₆ is selected from C₁ to C₈ alkyls, C₂ to C₈ alkenylsaryls, and substituted aryls; and R₄ is selected from phenylene,biphenyl, α,ω-diphenylalkane and —(CH₂)_(n)—, wherein n is an integerfrom 1 to 10; and wherein R₁, R₂, and R₃ can also form adamantyl or bornring systems.
 25. The method of claim 23, wherein the Lewis acid isselected from of aryl aluminum halides, alkyl-substituted aryl aluminumhalides, alkyl aluminum halides and a mixture thereof.
 26. The method ofclaim 23, wherein the Lewis acid is selected from of dialkyl aluminumhalide, monoalkyl aluminum dihalide, aluminum tri-halide, ethylaluminumsesquichloride, and a mixture thereof.
 27. The method of claim 23,wherein the Lewis acid is selected from AlCl₃, EtAlCl₂,Et_(1.5)AlCl_(1.5), Et₂AlCl, and mixtures thereof.
 28. The method ofclaim 23, wherein the dielectric constant of the diluent is greater than6 at 20° C.
 29. The method of claim 23, wherein the dielectric constantof the diluent is greater than 9 at 20° C.
 30. The method of claim 23,wherein the diluent is selected from methylcyclohexane, cyclohexane,toluene, carbon disulfide, ethyl chloride, methylchloride, methylenechloride, CHCl₃, CCl₄, n-butyl chloride, chlorobenzene, and mixturesthereof.
 31. The method of claim 23, further including the step ofhalogenating the terpolymer.
 32. The method of claim 31, wherein thehalogen is present in the terpolymer in the range of from 0.1 mole % to2.5 mole % based on the total moles of monomer derived units in theterpolymer.
 33. The method of claim 31, wherein the halogen is presentin the terpolymer in the range of from 0.2 mole % to 2 mole % based onthe total moles of monomer derived units in the terpolymer.
 34. Themethod of claim 23, further comprising combining a cure system includingat least one metal oxide, elemental sulfur, and optionally at least onesulfur based accelerator.
 35. The method of claim 23, further comprisingcombining a filler selected from carbon black, silica, alumina, calciumcarbonate, clay, mica, talc, titanium dioxide, starch, wood flower, andmixtures thereof.
 36. The method of claim 35, wherein the filler is ablend of carbon black and silica.
 37. The method of claim 23, furthercomprising combining a secondary rubber selected from natural rubber andpolybutadiene rubber, and mixtures thereof.
 38. The method of claim 23,further comprising combining at least one secondary rubber selected fromnitrile rubber, silicon rubber, polyisoprene rubber, styrene-butadienerubber, isoprene-butadiene rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched butyl rubber, star-branched halogenated(preferably brominated or chlorinated) butyl rubber,polyisobutylene-isoprene rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 39. A tiretread made by combining at least one filler; a sulfur cure system; atleast one secondary rubber; and at least one halogenated terpolymer ofC₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derived units,and p-alkylstyrene derived units.
 40. The tread of claim 39, wherein thecure system includes at least one metal oxide, elemental sulfur, andoptionally at least one accelerator.
 41. The tread of claim 39, whereinthe filler is selected from carbon black, alumina, calcium carbonate,clay, mica, talc, titanium dioxide, starch, wood flower, and mixturesthereof.
 42. The tread of claim 39, wherein the filler is a blend ofcarbon black and silica.
 43. The tread of claim 39, wherein the filleris present from 5 to 100 phr.
 44. The tread of claim 39, wherein thefiller is present from 30 to 80 phr.
 45. The tread of claim 39, whereinthe secondary rubber is selected from natural rubber and polybutadienerubber, and mixtures thereof.
 46. The tread of claim 39, wherein thesecondary rubber is selected from nitrile rubber, silicon rubber,polyisoprene rubber, poly(styrene-co-butadiene) rubber,poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched butyl rubber, star-branched halogenatedbutyl rubber, poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 47. The treadof claim 39, wherein the C₄ to C₈ isoolefin monomer is isobutylene. 48.The tread of claim 39, wherein the C₄ to C₁₄ multiolefin monomer isisoprene.
 49. The tread of claim 39, wherein the p-alkylstyrene isp-methylstyrene.
 50. The tread of claim 39, wherein the halogen ispresent in the terpolymer in the range of from 0.1 mole % to 2.5 mole %based on the total moles of monomer derived units in the terpolymer. 51.The tread of claim 39, wherein the halogen is present in the terpolymerin the range of from 0.2 mole % to 2 mole % based on the total moles ofmonomer derived units in the terpolymer.
 52. The tread of claim 39,wherein the terpolymer is brominated.
 53. The tread of claim 39, whereinthe secondary rubber is present from 5 to 90 phr.
 54. The tread of claim39, wherein the terpolymer is present from 10 to 100 phr.
 55. The treadof claim 39, wherein the filler is carbon black and the terpolymer ishalogenated.
 56. The tread of claim 55, having a DIN Abrasion Index ofat least 90 units.
 57. The tread of claim 55, having a tangent deltavalue of at least 0.50 at least −30° C.
 58. The tread of claim 55,having a tangent delta value of at least 0.38 at 0° C.
 59. The tread ofclaim 39, wherein the filler is silica.
 60. The tread of claim 59, alsoincluding a silane coupling agent.
 61. An elastomeric compositioncomprising at least one filler; a sulfur cure system; and at least oneterpolymer of C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefinderived units, and p-alkylstyrene derived units.
 62. The elastomericcomposition of claim 61, wherein the cure system includes at least onemetal oxide, elemental sulfur, and optionally at least one accelerator.63. The elastomeric composition of claim 61, wherein the filler isselected from carbon black, silica, alumina, calcium carbonate, clay,mica, talc, titanium dioxide, starch, wood flower, and mixtures thereof.64. The elastomeric composition of claim 61, wherein the filler is ablend of carbon black and silica.
 65. The elastomeric composition ofclaim 61, further comprising a secondary rubber, wherein the secondaryrubber is selected from natural rubber, polybutadiene rubber, andmixtures thereof.
 66. The elastomeric composition of claim 65, whereinthe secondary rubber is selected from nitrile rubber, silicon rubber,polyisoprene rubber, poly(styrene-co-butadiene) rubber,poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched butyl rubber, star-branched halogenatedbutyl rubber, poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 67. Theelastomeric composition of claim 61, wherein the C₄ to C₈ isoolefinmonomer is isobutylene.
 68. The elastomeric composition of claim 61,wherein the C₄ to C₁₄ multiolefin monomer is isoprene.
 69. Theelastomeric composition of claim 61, wherein the p-alkylstyrene isp-methylstyrene.
 70. The elastomeric composition of claim 61, whereinthe terpolymer is halogenated.
 71. The elastomeric composition of claim70, wherein the halogen is present in the terpolymer in the range offrom 0.1 mole % to 2.5 mole % based on the total moles of monomerderived units in the terpolymer.
 72. The elastomeric composition ofclaim 70, wherein the halogen is present in the terpolymer in the rangeof from 0.2 mole % to 2 mole % based on the total moles of monomerderived units in the terpolymer.
 73. The elastomeric composition ofclaim 70, wherein the terpolymer is brominated.
 74. The elastomericcomposition of claim 65, wherein the secondary rubber is present from 5to 90 phr.
 75. The elastomeric composition of claim 61, wherein theterpolymer is present from 20 to 100 phr.
 76. The elastomericcomposition of claim 61, wherein the filler is carbon black and theterpolymer is halogenated.
 77. The elastomeric composition of claim 76,having a DIN Abrasion Index of at least 90 units.
 78. The elastomericcomposition of claim 76, having a tangent delta: value of at least 0.50at −30° C.
 79. The elastomeric composition of claim 76, having a tangentdelta value of at least 0.38 at 0° C.
 80. The elastomeric composition ofclaim 61, wherein the filler is from 5 to 80 phr.
 81. The elastomericcomposition of claim 61, wherein the filler is from 50 to 80 phr.
 82. Atire comprising the composition of claim
 61. 83. A tread or sidewallcomprising the composition of claim 61.